In general, an industrial vehicle such as a wheel loader is widely used to excavate sand, gravel, and the like and load it into a dump truck.
A loading charge for the dump truck may be estimated depending on an amount of a material loaded into the dump truck, and when an industrial vehicle travels in a state that weight of a load exceeds the maximum loading capacity for the dump truck, a penalty may be imposed. Further, overweight bucket loading may cause damages to the wheel loader. Accordingly, in order to prevent overloading of the dump truck and reduce cost of maintaining the wheel loader, it may be required to accurately measure weight of loads.